Update monet.

crypto/encryptor_nss.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "crypto/encryptor.h"
+
+#include <cryptohi.h>
+#include <vector>
+
+#include "base/logging.h"
+#include "crypto/nss_util.h"
+#include "crypto/symmetric_key.h"
+
+namespace crypto {
+
+namespace {
+
+inline CK_MECHANISM_TYPE GetMechanism(Encryptor::Mode mode) {
+  switch (mode) {
+    case Encryptor::CBC:
+      return CKM_AES_CBC_PAD;
+    case Encryptor::CTR:
+      // AES-CTR encryption uses ECB encryptor as a building block since
+      // NSS doesn't support CTR encryption mode.
+      return CKM_AES_ECB;
+    default:
+      NOTREACHED() << "Unsupported mode of operation";
+      break;
+  }
+  return static_cast<CK_MECHANISM_TYPE>(-1);
+}
+
+}  // namespace
+
+Encryptor::Encryptor()
+    : key_(NULL),
+      mode_(CBC) {
+  EnsureNSSInit();
+}
+
+Encryptor::~Encryptor() {
+}
+
+bool Encryptor::Init(SymmetricKey* key,
+                     Mode mode,
+                     const base::StringPiece& iv) {
+  DCHECK(key);
+  DCHECK(CBC == mode || CTR == mode) << "Unsupported mode of operation";
+
+  key_ = key;
+  mode_ = mode;
+
+  if (mode == CBC && iv.size() != AES_BLOCK_SIZE)
+    return false;
+
+  switch (mode) {
+    case CBC:
+      SECItem iv_item;
+      iv_item.type = siBuffer;
+      iv_item.data = reinterpret_cast<unsigned char*>(
+          const_cast<char *>(iv.data()));
+      iv_item.len = iv.size();
+
+      param_.reset(PK11_ParamFromIV(GetMechanism(mode), &iv_item));
+      break;
+    case CTR:
+      param_.reset(PK11_ParamFromIV(GetMechanism(mode), NULL));
+      break;
+  }
+
+  return param_ != NULL;
+}
+
+bool Encryptor::Encrypt(const base::StringPiece& plaintext,
+                        std::string* ciphertext) {
+  CHECK(!plaintext.empty() || (mode_ == CBC));
+  ScopedPK11Context context(PK11_CreateContextBySymKey(GetMechanism(mode_),
+                                                       CKA_ENCRYPT,
+                                                       key_->key(),
+                                                       param_.get()));
+  if (!context.get())
+    return false;
+
+  return (mode_ == CTR) ?
+      CryptCTR(context.get(), plaintext, ciphertext) :
+      Crypt(context.get(), plaintext, ciphertext);
+}
+
+bool Encryptor::Decrypt(const base::StringPiece& ciphertext,
+                        std::string* plaintext) {
+  CHECK(!ciphertext.empty());
+  ScopedPK11Context context(PK11_CreateContextBySymKey(
+      GetMechanism(mode_), (mode_ == CTR ? CKA_ENCRYPT : CKA_DECRYPT),
+      key_->key(), param_.get()));
+  if (!context.get())
+    return false;
+
+  if (mode_ == CTR)
+    return CryptCTR(context.get(), ciphertext, plaintext);
+
+  if (ciphertext.size() % AES_BLOCK_SIZE != 0) {
+    // Decryption will fail if the input is not a multiple of the block size.
+    // PK11_CipherOp has a bug where it will do an invalid memory access before
+    // the start of the input, so avoid calling it. (NSS bug 922780).
+    plaintext->clear();
+    return false;
+  }
+
+  return Crypt(context.get(), ciphertext, plaintext);
+}
+
+bool Encryptor::Crypt(PK11Context* context,
+                      const base::StringPiece& input,
+                      std::string* output) {
+  size_t output_len = input.size() + AES_BLOCK_SIZE;
+  CHECK_GT(output_len, input.size());
+
+  output->resize(output_len);
+  uint8* output_data =
+      reinterpret_cast<uint8*>(const_cast<char*>(output->data()));
+
+  int input_len = input.size();
+  uint8* input_data =
+      reinterpret_cast<uint8*>(const_cast<char*>(input.data()));
+
+  int op_len;
+  SECStatus rv = PK11_CipherOp(context,
+                               output_data,
+                               &op_len,
+                               output_len,
+                               input_data,
+                               input_len);
+
+  if (SECSuccess != rv) {
+    output->clear();
+    return false;
+  }
+
+  unsigned int digest_len;
+  rv = PK11_DigestFinal(context,
+                        output_data + op_len,
+                        &digest_len,
+                        output_len - op_len);
+  if (SECSuccess != rv) {
+    output->clear();
+    return false;
+  }
+
+  output->resize(op_len + digest_len);
+  return true;
+}
+
+bool Encryptor::CryptCTR(PK11Context* context,
+                         const base::StringPiece& input,
+                         std::string* output) {
+  if (!counter_.get()) {
+    LOG(ERROR) << "Counter value not set in CTR mode.";
+    return false;
+  }
+
+  size_t output_len = ((input.size() + AES_BLOCK_SIZE - 1) / AES_BLOCK_SIZE) *
+      AES_BLOCK_SIZE;
+  CHECK_GE(output_len, input.size());
+  output->resize(output_len);
+  uint8* output_data =
+      reinterpret_cast<uint8*>(const_cast<char*>(output->data()));
+
+  size_t mask_len;
+  bool ret = GenerateCounterMask(input.size(), output_data, &mask_len);
+  if (!ret)
+    return false;
+
+  CHECK_EQ(mask_len, output_len);
+  int op_len;
+  SECStatus rv = PK11_CipherOp(context,
+                               output_data,
+                               &op_len,
+                               output_len,
+                               output_data,
+                               mask_len);
+  if (SECSuccess != rv)
+    return false;
+  CHECK_EQ(static_cast<int>(mask_len), op_len);
+
+  unsigned int digest_len;
+  rv = PK11_DigestFinal(context,
+                        NULL,
+                        &digest_len,
+                        0);
+  if (SECSuccess != rv)
+    return false;
+  CHECK(!digest_len);
+
+  // Use |output_data| to mask |input|.
+  MaskMessage(
+      reinterpret_cast<uint8*>(const_cast<char*>(input.data())),
+      input.length(), output_data, output_data);
+  output->resize(input.length());
+  return true;
+}
+
+}  // namespace crypto